DOUGLASR.OUSBORNE

SHIP SELF-DEFENSE AGAINST AIR THREATS

Recent trends in the proliferation of advanced-technology cruise missiles and aircraft and emphasis on multiservice littoral warfare have prompted renewed congressional and U.S. Navy interest in fleet self­ defense. This emphasis is focused on ensuring that expeditionary forces can sustain operations to accomplish their mission. The near-land, cluttered, terrain-masked littoral environment places the Navy within enemy striking range and can stress the ship systems' ability to detect, rapidly react to, and engage air threats. Operating in this environment against advanced cruise missiles and aircraft equipped with affordable penetration techniques such as low-altitude, high-speed maneuvers, and deceptive countermea­ sures can challenge the Navy's most advanced combat systems. Integration and evolution of existing radar, missile, and electronic warfare weapon system elements and the application of new sensor, weapon, and processing technologies can provide the fleet capability necessary to counter these threats in the near term and as they are expected to advance into the next century.

INTRODUCTION: A NEW FLEET EMPHASIS FOR THE LITTORAL ENVIRONMENT The U.S. Navy has witnessed countless changes ship system, owing to advances in coordinating threat throughout its long history, but few as dramatic as the arrival times and the limited number of fire control chan­ events within the last few years. The demise of the Soviet nels available in many frigate, destroyer, and amphibious Union and the rapid worldwide proliferation of advanced­ ships. The advent of patrol boat- and mobile truck­ technology weapons to Third World countries have result­ launched cruise missiles (similar to the SCUD ballistic ed in a rapid shift away from an emphasis on open-ocean missile Transporter Erector Launchers prevalent in global warfare to regional or limited conflicts involving Desert Storm) enables a "shoot and scoot" mode of op­ Third World nations in littoral waters. The recent Persian eration, thereby significantly reducing the effectiveness Gulf War is a clear example. of air superiority in mitigating the cruise missile threat. Such conflicts, frequently with geopolitical, religious, The littoral environment, depicted in Figure 1, is also or ethnic motivations, are more likely to occur as polit­ characterized by dense, commercial air traffic and mer­ ically unstable Third World nations are easily able to arm chant shipping, which present challenges to the combat themselves with state-of-the-art weapons. Faced with systems (and their operators) in distinguishing between economic recovery problems, the former Soviet Union hostile, neutral, and friendly tracks. The proximity to has begun to market its most advanced weapons and hostile shores and confined waters decrease the available aircraft, while western nations continue to export technol­ battles pace and warning time, increase clutter levels, ogy and weapons. In the recent Moscow! (11-16 August enable the employment of land-based electronic counter­ 1992) and Farnborough International2 (6-13 September measures, and increase the potential for unexpected at­ 1992) air shows, first-line former-Soviet Union weapons tack from land-based missile sites. and aircraft were for sale along with French, Chinese, To operate effectively in this environment, the required Italian, and Swedish advanced-technology weapons. The robust and integral self-defense capability must provide time lag between development and export is decreasing both a final anti air warfare (AAW) layer of defense when dramatically at the same time the number of producers operating in joint expeditionary operations and an auton­ is increasing, thus creating a very competitive market for omous capability. Although a frigate, destroyer, or air­ 3 weapons proliferation. ,4 This technology transfer defines craft carrier may be "under the umbrella" of an Aegis or and drives the regional/limited conflict threat. Desert New Threat Upgrade Combat Systems' Standard missile Storm clearly demonstrated the mature and effective envelope, an integral final layer of defense is needed to networks established in the Third World for procuring counter the sea-skimming missile threat. This is especial­ technology and weapons. It is expected that not only will ly true when the battle group/threat geometry prevents these networks strengthen with time, but that nations will engagement by the Standard missile ships and opportu­ develop increasing capabilities to modify imported weap­ nities for one ship to defend another against the sea­ ons and tailor them to their specific goals, even further skimming cruise missile are limited. In addition, the compounding the threat environment. Although fewer declining force structure as well as the littoral warfare threats are expected in anyone encounter, they can still environment results more often in situations where ships represent a high-intensity threat scenario to the defending operate independently or as small expeditionary forces

fohns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 125 D. R. Ousborne

Area defense

Landing area

Figure 1. Air defense in the littoral environment includes defense against cruise missiles, ballistic missiles, and aircraft in the diverse, dense-air-traffic, and cluttered near-land setting. A robust integral self-defense capability must provide a final layer of defense in joint expeditionary and traditional battle group operations as well as an autonomous capability for ships operating alone.

(e.g., in amphibious landing operations, blockade or major weapon system elements-detect, control, en­ barrier operations, or search and rescue operations). As gage-are required to operate effectively in this environ­ a consequence of these trends, every surface ship will be ment and counter the air threat. The near-land, high­ threatened by advanced sea-skimming cruise missiles in clutter environment, coupled with sea-skimming mis­ the regional/limited conflict environment. A robust, au­ siles, can overburden many of our existing sensors. Radar tonomous ship self-defense capability is essential for improvements in effective radiated power, aperture, these ships to be able to sustain operations and accom­ waveform flexibility, and signal processing are required plish their missions. to achieve adequate detection ranges. Improved integra­ This situation has produced a sharply focused empha­ tion and the increased automation of sensors, weapons, sis on fleet self-defense within Congress and the Navy. and fire control systems are essential to shorten reaction In response, the Navy created a Program Executive Office time and coordinate weapon response. In addition, ad­ for Ship Defense (PEO-SD) (recently expanded and rechar­ vanced command and control features are needed to tered as the Program Executive Office for Theater Air enable command personnel to direct and monitor the Defense) to coordinate efforts to improve self-defense overall operation of the combat system in this environ­ capabilities across the fleet. The regional/limited conflict ment with complex rules of engagement and identifica­ setting and advanced-cruise missile threats introduce sev­ tion requirements. Finally, advanced defensive missiles eral new warfighting challenges that necessitate combat with increased kinematics, fast flyout, multimode seekers system advances. Improvements in each of the three (e.g., semi-active homing and IR terminal), improved au-

126 fohns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) Ship Self-Defense Against Air Threats topilots and agility, and improved low-altitude ordnance commonplace. Trends in the cruise missile threat include fuzing are essential to countering the advanced-cruise the following: missile threat. 1. Smaller signatures and lower/higher altitudes. The Applied Physics Laboratory has assisted the Navy 2. Higher speeds and high-acceleration maneuvers. in creating a ship self-defense roadmap that identifies a 3. Radiation control and multimode guidance. technical approach for achieving the capability required 4. Advanced electronic countermeasures. to pace the threat through the incremental improvement 5. Hardening and relocation of vulnerable compo­ of existing elements, the development of critical new nents. elements, and their integration into the combat system. 6. Coordinated arrival times. This roadmap reflects, in part, the results of several These features are prominently promoted by several analytical, developmental, and evaluative programs con­ weapons producers, including French, Italian, and Swed­ 5 7 ducted over the past several years, including the Short­ ish manufacturers. - Supersonic, maneuvering, sea­ Range AAW Defense Systems Study (Kuesters Study, skimming missiles in development such as the French 1985), the Short-Range AAW Program (1986), and the Aerospatiale Anti-Naivre Supersonique (ANS)8 cruise NATO AAW Weapon System Program (1987-90). The missile exemplify the current trends. Reduced radar cross overall technical approach has been endorsed by the sections and lowlhigh-altitude flight profiles will be Office of the Chief of Naval Operations (OPNAV), Naval employed to reduce the available battlespace by limiting Sea Systems Command, and PEO-SD sponsors. Although the detection range and thus the time to react to and not all elements of the roadmap have been programmed engage the target. The high-speed and high-acceleration and funded, numerous specific recommendations have (high g) terminal maneuvers can challenge the weapon formed the basis for current design and development system performance by stressing the defensive missile's activities. kinematics and agility. In addition, multimode seekers (combinations of RF active, antiradiation homing, or IR THREAT TRENDS homing), as well as strict emissions control aimed at History has demonstrated that weapons developers minimizing detection opportunities and the effectiveness recognize the vulnerabilities of our defensive systems and of deceptive electronic countermeasures and decoys, can develop or evolve weapons to exploit the weaknesses. create further challenges for defensive electronic warfare Numerous examples can be found of this "responsive" or systems. As promoted by the French and Italian weapons "reactive" threat. Even as new developments have in­ producers, digital RF memory and repeater jammers will creased our capabilities, the weapons developers have make deceptive countermeasures very affordable pene­ continued their efforts to identify and exploit the limita­ tration techniques that can delay detection and challenge tions of our systems in an attempt to defeat them. Classic defensive weapon performance. Relocation and harden­ examples, shown in Figure 2, are the increasing cruise ing of vulnerable components can further stress defensive altitude of the high-cruise-dive missile threat and the very missile performance by reducing the ability of ordnance low-flying sea-skimming threat that attempt to penetrate to disable key cruise missile components. Additionally, defensive systems by flying above and below sensor and the French and Swedish weapons producers, Aerospatiale weapon envelopes. As the threat becomes more sophis­ and Saab Missiles, respectively, describe their ability to ticated, additional penetration aids will be increasingly ensure near-simultaneous arrival by controlling the thrust profile or through the use of trajectory waypoints with the 10 ANS, Exocet Block II,9 and RBS 15 antiship missiles, further stressing the combat system in terms of available firepower (number of fire control channels) and the abil­ ity to ensure the engagement of all targets in the raid (missile-to-target "pairing" efficiency).

COMBAT SYSTEM CHALLENGES The littoral environment and projected advanced threat developments will challenge the combat system in terms of detection range, reaction time, and defensive missile performance against the advanced threats (Fig. 3). The near-land, high-clutter environment and low-altitude, small radar-cross-section cruise missiles will restrict the sensor detection range, thereby limiting the battles pace in which the defensive systems must react. Relatively long reaction times will delay missile launch against the Figure 2. The reactive threat attempts to penetrate the weapons threat and further reduce the battles pace and time to envelope and exploit system vulnerabilities with advanced pen­ engage the target. In this situation, slow average-speed etration techniques such as low-altitude, semi-ballistic, and ballis­ tic profiles, stealth, electronic countermeasures, and high-accel­ defensive missiles will result in very short-range inter­ eration maneuvers. Worldwide cruise missile proliferation and cepts, risking debris impact and ownship damage. Defen­ technology transfer define and drive the threat environment. sive missile performance will also be stressed against

fohns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 127 D. R. Ousborne

Constraints Slow missiles Long reaction times Very short-range intercepts delay missile launch Reduced performance against maneuvering targets

Figure 3. Projected combat system chal­ lenges in engaging advanced supersonic Short detection ranges sea-skimming cruise missiles include limit battlespace short detection ranges, long reaction times, and defensive missiles with re­ duced performance against advanced, Reduced system highly maneuvering threats. Effective reaction time defense requires detection, command and The System Solution control , hardkill and softkill system en­ hancements, and increased system au­ tomation and integration. Faster missiles Greater intercept ranges Effective against r=s~~~ __ maneuvering targets

advanced maneuvering targets because of limited kine­ the ship class/threat categories. The allocation of the matic capabilities and relatively long guidance and air­ mission requirements, as suggested in Figure 5, to the frame response time constants. detect, control, and engage elements of the combat sys­ A balanced, integrated combat system solution is es­ tem emphasizes the interrelationships of the elements and sential to defeating the air threat in this environment. the extent of the modifications required to counter the Improvement in anyone element alone is inadequate. advancing threat effectively. Requirements were estab­ Increased target detection ranges, decreased system reac­ lished in two time frames-1998 and beyond 2004-such tion times, advanced command and control features, and improved hardkill and electronic warfare weapons can be developed, integrated, and coordinated to provide an effective defense. The improvement trends that can be realized with these upgrades are shown in Figure 4. The probability of escaping a significant hit (probability of Advanced combat successfully defending against all targets in the raid) is shown as a function of the target detection range (which is influenced by the target radar cross section, altitude, speed, and the environment) for both a baseline and an advanced combat system. The threat raid consists of multiple advanced low-altitude, supersonic, maneuvering cruise missiles; the critical combat system characteristics include system reaction time, defensive missile launch rate, flight time to intercept, endgame effectiveness, and the number of available illumination channels. Baseline combat

SELF-DEFENSE REQUIREMENTS The littoral environment and threat trends described previously influence the mission and system-level re­ OPNA v quirements. In establishing mission requirements, Detection range grouped the U.S. ship classes into high, medium, and low risk categories on the basis of their expected employment Figure 4. The projected combat system performance against and anticipated targeting by hostile forces. The require­ multiple advanced low-altitude, supersonic, maneuvering cruise ments took the form of specified probabilities of escaping missiles depends on the detection range as well as the system a significant hit for a specific raid density (number of reaction time, defensive missile launch rate, flight time to intercept, endgame effectiveness, and number of available illumination targets and arrival rate) with threat parameter bounds channels. Adequate performance can be achieved with detection, such as speed, altitude, radar cross section, IR signature, command and control, defensive missile, and electronic warfare and terminal maneuver. The requirements varied among upgrades associated with the advanced combat system.

128 Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) Ship Self-Defense Against Air Threats

Detect Sensor suite performance Long detection range Full surveillance volume Fast track-update rate High-accuracy track Sensor suite elements Improved TAS/SPY-1 radars HS/wS multifunction radar Horizon IR sensor System-Level Requirements SLQ-32/AIEWS PESM sensor Mission survivability Probability of escaping ship damage Control Raid density Fast reaction time (detect to launch) Increased automation Figure 5. The overall combat system Threat parameter bounds Sensor integration and control mission-survivability requirements can be High speed High-accuracy IR and PESM cue allocated to the major elements (detect, Very low altitude Low time latency control, engage) of the weapon system. Small radar cross section Threat evaluation/weapon assignment The individual element requirements and Low IR signature Coordination of hardkill/softkill assets threat parameter bounds determine the High-g terminal maneuver necessary technology and the extent of the modifications required. TAS = Target Maintain performance in electronic Engage Acquisition System, HS/WS = Horizon countermeasures Missile Search/Weapon Support, AIEWS = Large intercept range Long-range stand-off jamming Advanced Integrated Electronic Warfare Onboard jamming Fast average speed System, PESM = Precision Electronic Sup­ High maneuverability Deceptive countermeasures port Measures. High single-shot kill Sustainability probability Ready capacity to handle Fast warm-up multiple raids Launcher Large ready loadout Short launch interval

Firepower capacity Many simultaneous missiles Many terminal illumination channels

Electronic warfare elements Onboardloffboard RFIIR coverage

that the resultant systems will pace the threat as it advanc­ SELF-DEFENSE ENHANCEMENT ROADMAP es. The 1998 requirements were established from both a top-down threat and mission survivability perspective as To satisfy self-defense requirements, existing system well as a bottom-up viewpoint of the technological and elements must be upgraded and new critical develop­ design changes achievable in that time frame. The 2004+ ments must be initiated. The emphasis within the detec­ requirements, on the other hand, require the introduction tion system is no longer limited to radar frequency bands, of advanced radar and missile guidance and seeker tech­ but rather is multispectral in nature. Particular emphasis nology to counter the projected threat. is placed on an active-element, phased-array, horizon­ Sensor system requirements are specified in terms of emphasis multifunction radar, a horizon-scanning IR sys­ detection range, countermeasures resistance, track accu­ tem, and a precision electronic support measures sensor racy, and timeliness. The command and control require­ to achieve the required detection ranges against small ments include reaction time (i.e., time from detection to radar-cross-section threats at sea-skimming altitudes in missile launch), data latency, data fusion, and cueing the cluttered land background of the littoral environment. accuracy. Engagement system requirements are parti­ Increased automation and multispectral data integration tioned into hardkill (e.g., missile or gun) and softkill (i.e., are essential to coping with the reduced battlespace and electronic warfare) requirements and address the mis­ short-range target detection. Complex rules of engage­ sile's average speed, maneuverability, agility, single-shot ment and target identification in the Third World/regional probability of kill, number of fire control channels, decoy conflict environment require advanced command and response time, accuracy of electronic support measures, control concepts to permit the system operators to man­ and frequency coverage. These balanced and integrated age and tailor the weapon system to the threat and op­ requirements, when combined at the combat system level, erational tactics with preestablished doctrine rather than achieve the mission survivability goals. attempt to react to the threat in real time. Advanced

fohns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 129 D. R. Ousborne missiles with increased average speed (shorter missile Defense System (SSDS) Mk I, Mk II, and Mk III. Each flight times), with adequate maneuverability margin, and capability is designed to provide effective defense against with increased agility are essential to countering ad­ the threat anticipated for that time frame and, thereby, vanced highly maneuverable threats. Electronic warfare pace the threat as it advances through incremental im­ system upgrades are required to provide effective on­ provement in combat system performance. Also shown board countermeasures and offboard decoys to contribute in Figure 6 are candidate ship classes for each weapon to defense against the anticipated threat-raid densities. system upgrade based on the intended mission and re­ Integration of electronic warfare necessitates advanced quirements established by OPNAV for each ship class. The hardkilllsoftkill weapon coordination mechanisms not specific upgrades for each SSDS configuration depend on only to avoid mutual interference that degrades perfor­ the existing combat system configuration (specific radars, mance, but also to enhance the total combat system ef­ missiles, guns, electronic warfare, decoys, and command fectiveness through cooperation. Softkill techniques can and control elements) and the ease of integration of new be employed, for example, to increase the target's vul­ elements. The specific configurations will, therefore, nerability to hardkill engagement. vary among ship classes. The Program Manager for Ship The roadmap or technical approach to achieving self­ Self-Defense has established a Ship Self-Defense Master defense goals is shown in Figure 6. Three time frames Plan Analysis Working Group that is continuing to assess and capabilities are addressed: an immediate capability the most advantageous upgrades for each ship class on enhancement for the 1995 time frame, a near-term capa­ the basis of warfighting benefit and cost considerations. bility in 1998, and a far-term capability beyond 2004. The The analysis group includes participants from the Naval development path achieves the far-term capability while Surface Warfare Center, the Naval Research Laboratory, at the same time enables near-term improvements. The and APL. Existing hardkill and electronic warfare weapon upgraded capabilities have been designated the Ship Self- system performance models have been upgraded, and

Immediate Near-term Far-term Today ) capability capability capability

Standard missile Ship signature reduction Evolved Seasparrow Phase I missile Near-term capability Seasparrow missile Rolling Airframe missile/fuze Improved TAS and AN/SPQ-9 radars + Phalanx Blk 0/1 upgrade Horizon I R sensor HS/wS multifunction radar AN/SLQ-32 Phalanx Blk I Mk 99 acquisition & track capability Evolved Seasparrow Phase II missile Decoys Sensor integration Data fusion Precision ESM sensor AN/SLQ-32 advanced capability Phalanx Blk 1/3 Advanced integrated EW system Independent Ship signature reduction Advanced decoy launcher systems Deceptive ECM/decoy integration Improved decoys (chaff, IR) AN/SLQ-32 Phase E Advanced decoys HKlSK doctrine (RAIDS, Aegis) Active RF decoy Integrated..,;..H..,;..KI.:....S.:....K______--1 Trainable decoy launcher Ship Self-Defense System Mk III HKlSK coordination Ship Self-Defense System Mk I Cooperative engagement

Ship Self-Defense System Mk II

Candidate Number SSDS SSDS SSDS ship class of ships Mk I Mkll Mk III LSD 41 16 V///,/// ////L'L:: LHA 1 5 LCC 19 2 LHD 1 6 FFG 7-49 21 FFG50 12 '////// /////// AOElAOR 12 CG 47-51 5 CG 52 22 DDG 51 45 DD963 31 CV/CVN 12 - D Class installation t:2J Partial class installation Figure 6. The self-defense enhancement roadmap is summarized, showing the time-phased introduction of the Ship Self-Defense Systems Mk I, II, and IIi. These capability enhancements include hardkill and softkill upgrades, their integration, and increased automation. Potential ship class installations and the number of systems required are identified; specific configurations vary among ship classes. Ship class descriptions can be found in Ref. 11 . ECM = electronic countermeasures, HKlSK = hardkili/softkill, TAS = Target Acquisition System, HS/wS = Horizon Search/Weapon Support, ESM = electronic support measures, EW = electronic warfare, SSDS = Ship Self-Defense System, RAIDS = Rapid Antiship Missile Integrated Defense System.

130 Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) Ship Self-Defense Against Air Threats

hardkilVsoftkill integration techniques are being devel­ radar, an improved AN/SPQ-9 radar, and a horizon-empha­ oped to permit detailed combat-system-level perfor­ sis IR sensor to aid in the detection of the supersonic threat mance assessment, configuration alternative analysis, and at adequate ranges to enable engagement. The recom­ configuration definition. mended near-term configuration also includes the intro­ duction of a continuous-wave acquisition and track sys­ SHIP SELF-DEFENSE SYSTEM Mk I tem in the Aegis Mk 99 illuminators. This system pro­ vides for horizon search by exploiting the low-elevation The immediate goal is the rapid deployment of an propagation advantage inherent at X-band. The horizon enhanced self-defense capability on those ship classes IR sensor provides an opportunity for multispectral data currently without a short-range missile system. Driven by fusion and precision cueing of the AN/SPY-l phased-array the 1995 time frame, the upgrades necessarily include radar and the Mk 95 or Mk 99 fire control radars. In­ off-the-shelf capabilities and the integration of existing creased integration also enables data fusion at the weap­ combat system elements. The upgrades include the ad­ ons level, combining radar range with precision IR angle dition of the Rolling Airframe missile (RAM) with its dual­ data to support missile initialization, midcourse guid­ mode seeker (antiradiation and IR homing) and a fuze ance, or terminal illumination. The SSDS Mk II also in­ upgrade for improved performance against the near-term corporates the Phalanx Block I Baseline 3 upgrade, which sea-skimming threat. In addition, the Close-in Weapon includes a surface target engagement mode, a forward­ Gun System (Phalanx) will be upgraded to the Block I looking IR sensor, a new digital signal processor, and a configuration to increase the elevation coverage, search search-through-track antenna capability. sensitivity, magazine size, and gun firing rate. The Pha­ Additional electronic warfare upgrades and new ele­ lanx search radar, AN/SPS-49 search radar, and AN/SLQ-32 ments are identified in SSDS Mk II, including AN/SLQ-32 electronic warfare system will be integrated through an electronic support measures sensitivity improvement, an architecture based on a local area network such that all offboard active RF decoy such as Nulka, and a trainable sensors can contribute to both RAM missile and Phalanx decoy launcher. One of the constraints of offboard deco~s gun engagements. An SSDS Mk I demonstration capability is the geometrical restrictions relative to the threat aXIS, was installed on USS Whidbey Island (LSD 41 ) during the ship's heading, wind, and fixed azimuth/elevation launch Spring of 1993; it demonstrated significantly improved tubes. A trainable decoy launcher will ameliorate these combat system performance against multiple target raids. constraints, thereby providing improved performance. The recommended SSDS Mk I capability also includes Concurrent with these upgrades is the next layer of so­ electronic warfare upgrades such as a reduced ship radar phistication in hardkilVsoftkill coordination of deceptive cross section achieved by the application of radar-absorb­ electronic countermeasures with missile engagements ing material, advanced deceptive electronic countermea­ to increase the vulnerability of the target to hardkill sures in the AN/SLQ-32, integration of deceptive counter­ engagement. measures with offboard decoys to facilitate threat seeker The SSDS Mk II capability includes the Evolved Sea­ transfer from the ship to the decoy, and deployment of sparrow missile and is, therefore, recommended for in­ NATO available improved decoys such as the Sea Gnat tegration into the NATO Seasparrow Surface Missile Sys­ Mks 214 and 216 seduction and distraction chaff and tem fleet, including the LHD 1, AOE, AOR, DD 963 , and CVI IR Torch decoys. These electronic warfare weapons are CVN ship classes. The proposed Mk II configuration for coordinated with hardkill weapons using relatively sim­ the DD 963, for example, is shown in Figure 7. It incor­ ple doctrine to prevent interference. Although intended porates both new and upgraded combat system elements SSDS for the Mk I configurations, the electronic warfare and their integration. The SSDS Mk II capability is also upgrades can be implemented in other ship classes as recommended for introduction in the Aegis co 52 and DDO well, providing some enhanced capability before receiv­ 51 ship classes to provide an essential additional layer of ing the SSDS Mk II capability upgrades described later. defense against the advanced supersonic sea-skimming The SSDS Mk I is recommended for integration in ship missile. These ship classes will be upgraded to the Mk classes that currently have no short-range missile system III configuration in the far term as described in the next such as the LSD 41, LHA 1, LCC 19, CO 47-51, and FFO 7 ship section. classes (Fig. 6). (Ship class descriptions can be found in Ref. 11.) The addition of the RAM missile significantly SHIP SELF-DEFENSE SYSTEM Mk III improves their combat capability. Future upgrades to the The far-term capability shown in Figure 6 incorporates SSDS Mk I ships include electronic warfare upgrades but advanced technology elements and consequently is pro­ not the Mk II or Mk III configurations. jected beyond 2004. This capability has been design.a~ed SSDS Mk III and is an upgrade of the Mk II capabIlIty. SHIP SELF-DEFENSE SYSTEM Mk II The Mk III concept incorporates an advanced wideband, The SSDS Mk II enhancement incorporates both up­ active-element, phased-array multifunction radar that graded and new weapon system elements, including the performs horizon search as well as midcourse uplink a.nd first phase of the Evolved Seasparrow missile with in­ terminal illumination for engagement support. The sohd­ creased kinematics and agility to counter a highly maneu­ state, multifunction radar will enable near-horizon detec­ vering target. The recommended SSDS Mk II capability tion ranges against the reduced--cross-section sea-skim­ includes an improved Target Acquisition System Mk 23 ming threat and provide multiple channels for pulsed

Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 131 D. R. Ousborne

Detect [=:J Control [=:J Engage

Figure 7. As an example of the Ship Self-Defense System Mk II configuration , the proposed DO 963 upgrade includes both new and modified combat system elements. Multiple sensors and weapons are automated and extensively integrated through an architecture based on local area network technology to achieve the required capability. TAS = Target Acquisition System , CEC = Cooperative Engagement Capability, VLS = vertical launching system, RAM = Rolling Airframe missile, ESM = electronic support measures, ECM = electronic countermeasures, LAN = local area network, FDDI = fiber distributed data interface.

continuous-wave illumination for sample-data terminal data integration to support target engagement with either homing. hardkill or softkill weapons. Advanced oftboard decoys, The SSDS Mk III concept also includes the second millimeter-wave countermeasures, and IR countermea­ phase of the Evolved Seasparrow missile with its im­ sures are also included in the SSDS Mk III capability. proved sensitivity RF and imaging IR multimode seeker, improved ordnance, and a boosted variant for increased HORIZON-EMPHASIS SENSORS AND NEW kinematic performance and range in vertical launching system applications. The phase-two missile seeker and TECHNOLOGY radome will be matched to the broadband illumination The horizon-emphasis sensors necessary to pace the capabilities of the shipboard active radar to achieve en­ advancing threat include both upgrades to existing radars hanced performance in low-altitude, multipath, and clut­ and new developments in radar, IR, and electronic support ter-rich engagement environments. measures sensors, as identified in Figure 8. Among the The Advanced Integrated Electronic Warfare System potential radar upgrades is the addition of a continuous­ will be fully integrated into SSDS Mk III, including an wave acquisition and track capability for the Aegis fire advanced precision electronic support measures system control system. The upgrade concept is based on the using phase interferometer technology and improved existing Terrier and Tartar fire control radars and adds an sensitivity to generate very precise azimuth and elevation X-band receiver to the Aegis illuminator to provide an track data for precision cueing of the phased array, data adjunct search, detection, and track sensor. The fire con­ fusion, and weapons employment. The precision elec­ trol radar can then be used in horizon search to detect sea­ tronic support measures data can be correlated with IR skimming threats using the inherent Doppler-based sub­ and radar data for enhanced target identification, im­ clutter visibility (due to Doppler filter processing) and X­ proved tactical situation awareness, and weapon-level band low-altitude propagation advantage (16-27 dB im-

132 Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) Ship Self-Defense Against Air Threats

Present day Immediate Near term Far term

Candidate Number Fire Control System Horizon IR sensor Precision ESM sensor Horizon Searchl ship class of ships upgrade Improved TAS radar Improved AN/SPQ-9 radar Weapon Support radar

LSD 41 16 LHA 1 5 LCC 19 2 LHD 1 6 FFG 7-49 21 FFG 50 12 AOE/AOR 12 CG 47-51 5 CG 52 22 DDG 51 45 DD963 31 CV/CVN 12

Class installation E2] Partial class installation Figure 8. The horizon-emphasis sensors necessary to provide adequate detection ranges and weapon support against the advanced threat in the cluttered, electronic countermeasures environment include radar, horizon IR , and precision electronic support measures sensor upgrades and new technology application (Figs. 10-12). The integration of these sensors in each ship class is determined by the performance requirements of the Ship Self-Defense System Mk I, II, and III capabilities. Ship class descriptions can be found in Ref. 11 . TAS =Target Acquisition System, ESM = electronic support measures.

provement over typical search radar frequencies [S- and L-band] at 10 nmi, depending on radar height and target ill height-see Fig. 9). The X-band receiver also provides ~ o 0 a noncooperative target recognition capability for track t5 co identification based on radar signal modulation tech­ ~ -10 o niques. This feature provides an additional means for the ~ combat system and its operators to identify targets in the g> -20 cluttered littoral environment where it is difficult to dis­ oCl. a. -30 criminate hostile threats from neutral and friendly air ~ traffic. ::: 6 -40 To ensure adequate target detection ranges against the ~ advanced threat on other ship classes (Fig. 8), upgrades -50 ~~--~--~--~--~--~--~~~~~~ of the Target Acquisition System Mk 23 and AN/SPQ-9 o 4 8 12 16 20 radars are required. The upgrades include advanced dig­ Range (nmi) ital signal processing for increased sensitivity and sub­ clutter visibility, increased average power, and increased aperture. Both radar upgrade concepts employ a scan­ back feature providing single-scan detection by forming Figure 9. The low-elevation two-way propagation factor is shown for several frequencies at a radar antenna height of 100 ft for a sea­ an additional beam offset in azimuth following initial skimming cruise missile at a 12-ft altitude. The X-band advantage track detection. Given this nearly simultaneous track over S- or L-band at a detection range of 10 nmi is as great as 16 dwell and coherent digital signal processing, Whitfield or 27 dB, respectively.

Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 133 D. R. Ousborne confirmation techniques 12 can be used to enhance track vantages in detecting targets in multipath environments detection and achieve a 6-10 dB improvement, depend­ and essentially eliminates the multipath-induced signal ing on radar frequency and target speed. These features fades that otherwise degrade missile semi-active terminal decrease the track formation time from several seconds homing. Advanced digital signal processing provides sig­ to less than one second. The improved Target Acquisition nificant electronic countermeasures immunity with adap­ System radar also includes a larger antenna to provide tive null beam-forming for jammer suppression and de­ increased gain, better performance in electronic counter­ ceptive illumination. Pulsed continuous-wave illumina­ measures environments, and coarse elevation in addition tion provides the equivalent of multiple fire control chan­ to range and azimuth information. nels. This feature permits time multiplexed illumination A critical element of the SSDS Mk III advanced capa­ of several tracks during the same terminal homing inter­ bility is the Horizon Search/Weapon Support radar, val for multiple concurrent engagements. The solid-state which performs wideband horizon search and precision phased-array radar will be developed in two configura­ track, uplink and terminal illumination support for the tions that differ in aperture size and number of transmit! Evolved Seasparrow missile, and terminal illumination receive modules. The large-array radar is matched to the for the Standard missile (in ships configured with both Aegis Combat System with its requirement to support the missiles). The multifunction radar concept combines key long-range Standard missile as well as the Evolved Sea­ features of several older technologies (Fig. 10) with sparrow missile. The smaller array is adequate for those solid-state active-element radar technology to achieve combat systems that employ only the Evolved Seaspar­ low-loss, ultrastable, wideband operation. Advanced row missile. This use will result in a lower cost system beam-forming, pUlse-Doppler, and other flexible wave­ for ships such as Spruance class destroyers (DD 963) or forms, in addition to a high effective-radiated-power newly constructed amphibious ships. level, will result in near-horizon detection ranges against Multispectral target detection and data fu sion are even the most stressing sea-skimming threats, especially also required to provide adequate detection ranges when cued. Wideband operation provides additional ad- and, therefore, adequate battles pace for weapon response

Multifunction radar Active radar Tracking radar Minimum reaction time technology (fire control) Multiple target tracking Very low loss Ultrastable master oscillator Weapon midcourse control Wideband operation Clutter-free operation Adaptation High system stability Precision target track Waveform flexibility Missile terminal illumination Advanced beam forming

Solid-state antiair warfare radar Wideband multifunction phased array Wideband horizon search and local volume preCision track Missile midcourse control and "smart" terminal illumination Transmit and receive ECCM and deception

Figure 10. The Horizon Search/Weapon Support multifunction radar is a mix of old and new technologies. The application of solid-state, active-element radar technology significantly enhances performance in terms of low loss, high stability, wideband operation, waveform flexibility, and electronic countermeasures resistance. ECCM = electronic counter countermeasures.

134 Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) Ship Self-Defense Against Air Threats against the stressing, reduced-cross-section sea-skim­ denied because of short-range detections of small-cross­ ming threats. A horizon IR sensor is, therefore, essential section, high-speed threats. to the enhanced ship self-defense capability. It is also a A precision electronic support measures sensor is combination of old and new technology, as shown in the third element of the SSDS sensor triad. Like the Figure 11, with 360° azimuth coverage, up to 3° or 4° horizon IR sensor, it is a mix of old and new technology of elevation coverage, and a I-Hz scanning rate. Concen­ (Fig. 12). Unlike the existing AN/SLQ-32, it is pitch tration on the horizon to provide added detection capa­ and roll stabilized and provides azimuth and elevation bility against the sea-skimming threat allows the optics data of milliradian accuracy and improved sensitivity to be lightweight in comparison with the AN/SAR-8 IR using phase interferometry techniques. The sensor also search and track set (which attempted to cover high el­ provides instantaneous frequency measurements using evation as well) and, therefore, to be mounted high on the advanced microprocessors and transputers to achieve mast, further extending the horizon. Focal-plane-array high-speed parallel processing of large amounts of data. technology with a large number of detectors provides When combined with a Precision Passive Detection and increased sensitivity (10-12 dB improvement) and two Tracking System,13 precise angle and angular rate data bands provide detections on the basis of rocket motor are generated and can be used for automatic radar-to­ plume and aerodynamic heating. Fast scan rates compat­ electronic support measures track correlation. Various ible with today's high-speed digital signal processors will discriminants such as frequency, pulse repetition interval be used. With its milliradian angular accuracy, the hori­ and type, scan rate, and pulse width are also processed zon IR sensor will provide precision cues to mechanically and used for enhanced target identification. As with the steered or phased-array radars, enabling them to use tai­ precision IR data, electronic support measures data pro­ lored waveforms and thus increase their performance by vide precision cues that result in improved performance 8-10 dB. This precision azimuth and elevation track data and can be used for weapons employment. can also be used for missile guidance and illuminator pointing. Against the supersonic, reduced-cross-section ARCHITECTURAL TECHNOLOGY threat, the horizon IR sensor in some environments will INSERTION provide declaration ranges nearly double those of today's To meet mission requirements, achieve improved in­ surveillance radars. This improvement enables engage­ tegration, and provide advanced command and control ments to occur in situations that may have otherwise been features, significant processor and console upgrades are

Staggered linear detector array

AN/SAR-8 Focal-plane array technology Passive search and track-while-scan Increased number of Automatic mid-band detection and track detector elements Mature signal processing algorithms Improved sensitivity Clutter rejection Faster scan rate Large elevation coverage VLSI signal processing

Horizon IR Dual band 360 0 azimuth x 30 elevation search and track Improved sensitivity (x10 improvement) Lightweight, mast-mounted optics Very mature, high-speed signal processing

Figure 11. Engagement battlespace lost owing to the high-speed, low-altitude, and small radar-cross-section supersonic cruise missile can be regained through multispectral data fusion and radar cueing using focal-plane-array IR sensor technology with improved sensitivity and a faster scan rate. Lightweight optics permit high mast mounting, which further extends the horizon and detection range against the high-speed (thus "hot" IR signature) threat. VLSI = very large scale integrated circuit.

Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 135 D. R. Ousborne

ESM (AN/SLQ-32) Tracker Advanced Passive detection processing Interferometer Non-scanning technology Microprocessors Roll stabilized and transputers Phase interferometry Instantaneous frequency Automatic centroiding Parallel processing measurement and tracking Pulse repetition interval (PRI), Improved sensitivity PRI typing, scan-rate estimation Precision mUlti-target tracking

Precision passive detection and tracking system

Full band operation Precision azimuth, elevation, and rates Pitch and roll stabilization Reduced multipath Automatic ESM/radar correlation Enhanced discriminants for target identification

Figure 12. As with the horizon IR sensor (Fig. 11), precision electronic support measures data can extend detection ranges and enhance defense against cruise missiles through data fusion and cueing. Interferometer technology enables improved sensitivity; precision azimuth, elevation, and rate tracking; and enhanced discriminants for target identification. ESM = electronic support measures.

essential. Many of today's systems, however, have lim­ scheduling, guidance, control, and engagement kill as­ ited growth potential as a consequence of the point-to­ sessment. point architectures, limited input/output channels, and The SSDS Mk II and III systems will employ fully centralized processors. The required architecture must distributed microprocessors grouped in clusters, connect­ satisfy the low-latency requirements driven by the threat, ed through a combination of backplane buses and net­ be capable of growth, and take full advantage of current works. This architecture achieves the reaction time (50% technology in the fields of computer and display process­ reduction from today's most advanced systems) and low ing (Fig. 13). data latency required to provide adequate performance The SSDS Mk I incorporates fiber-optic local area net­ against the specified raid densities and to enable multi­ works to support the required redundancy, casualty re­ spectral weapon-level data integration. The open archi­ covery, and higher data throughput to handle the in­ tecture thus created ensures adequate reserves in time and creased shipboard information to be processed, dissem­ core capacity and permits the use of enhanced man­ inated, and integrated. It uses both Fiber Distributed Data machine interfaces through the addition of advanced Interface and Ethernet-based local area networks to in­ workstations. It also enables the relatively easy introduc­ terconnect command workstations and the weapon sys­ tion of new elements, allowing the combat system to keep tem elements via local area network access units. Distrib­ pace with new technology and its application to counter­ uted microprocessors enable increased automation and ing the advancing threat. integration, and Sun-based workstations present the operators with advanced, multiwindow color displays EVOLVED SEASPARROW MISSILE of map, symbology, status, and doctrine data. These The Evolved Seasparrow missile, depicted in Figure features enable the combat system operators to manage 14, is critical to countering the advanced sea-skimming the automated systems effectively using fast-response, and maneuvering cruise missile threat. A two-phase de­ screen-oriented controls. The architecture also permits velopment provides a near-term missile capable of coun­ distributed sensor integration that enables multiple radar, tering the advanced maneuvering threat and a Phase II IR, and electronic support measures sensor contact data missile upgrade to defeat the far-term threat and match to be fused into a single track and used in weapons the capabilities of the broadband multifunction radar. The

136 fohns Hopkins APL Technical Digest. Volume 14. Number 2 (1993) Ship Self-Defense Against Air Threats -

Low latency Distributed processing Open architecture Microprocessor clusters Workstations

Microprocessor cluster

'" utl'id , Lee 19 al b FFG 7-49

Figure 13. The system requirements allocated to the command and control element can be achieved through the insertion of current technology in computer processing, networking, and displays. Increased integration, data fusion, distributed-microprocessor-based processing, and enhanced man- machine interfaces enable rapid-response, low-data-Iatency weapon system operations. Ship class descriptions can be found in Ref. 11. NTDS = Naval Tactical Data System, LAN = local area network.

near-term missile is being developed in a joint effort by tion (i.e., four missiles per cell), X-band midcourse several nations of the ATO Seasparrow Consortium, in­ guidance uplink, and pulsed continuous-wave illumina­ cluding Australia, Belgium, Canada, Germany, the Neth­ tion for semi-active terminal homing. These options erlands, Norway, Portugal, Spain, and the United States. permit the missile to use the full capability of the mul­ The near-term Evolved Seasparrow missile (Fig. 15) tifunction Active Phased-Array Radarl4 being developed is an improved, larger-diameter (ten-inch versus eight­ in the Netherlands. The U.S. unique options include inch), quad-packable rocket motor with tail control pro­ modified ordnance to improve performance against su­ viding twice the average missile speed, improved kine­ personic, sea-skimming threats, a dual-mode terminal matic capability, and thrust vector control for rapid tip­ homing seeker (semi-active RF/IR) with improved sensi­ over after vertical launch. Only minimal changes to the tivity for low-signature targets, and S-band midcourse existing RIM-7PIR guidance section are necessary to ac­ guidance for integration into the Aegis Combat System. commodate the rocket motor improvements. These The near-term Evolved Seasparrow missile will be com­ changes include an improved autopilot (for reducing the patible with the NATO Seasparrow Mk 29 guided missile missile's time constant) and a digital inertial measure­ launching system as well as the Mk 41 and Mk 48 vertical ment unit. The improved missile agility and guidance launching systems. It will be integrated into the SSDS capability reduce the miss distance and, thus, increase the Mk II. effectiveness against advanced maneuvering targets. In­ The second phase of the Evolved Seasparrow missile ternational and unique U.S. options are identified for the development includes a larger-diameter (ten-inch) front near-term missile, motivated primarily by combat system end with an improved warhead and fuze, a dual-mode integration requirements. International options include a seeker with an RF capability matched to the broadband Mk 41 vertical launching system quad-pack configura- Horizon Search/Weapon Support multifunction radar,

Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 137 D. R. Ousborne

Increased average speed Improved autopilot and agility Multipack and fast warm-up vertical launch Tail control Ordnance mods and midcourse desirable

Midcourse guidance Semi-active broadband Imaging IR terminal Improved ordnance

de MEKO ..,.I CPF

[ rM

Figure 14. Evolution of the NATO Seasparrow missile (RIM-7) is critical to countering the advanced sea-skimming, maneuvering cruise missile threat. A two-phase development will yield a kinematically enhanced, agile, tail-controlled missile that can be launched from both trainable and vertical launchers in the near term and improved ordnance, boosted and nonboosted variants with a multimode seeker for the far term. Candidate ships, both U.S. and foreign, are identified. Ship class descriptions can be found in Ref. 11.

and an imaging IR seeker. The Phase II missile also has ness on alertment time (decoy deployment times), relative a midcourse guidance capability via the Horizon Search! geometry (threat axis, launch tube, relative wind), ship Weapon Support radar uplink and is compatible with signature (radar, IR, RF emissions), and specifIc threat pulsed continuous-wave illumination for increased fIre­ identifIcation and seeker characteristics (for tailored de­ power. It has a boosted and a non boosted confIguration ceptive electronic countermeasures response). In many for continued compatibility with the Mk 41 and Mk 29 circumstances, however, electronic warfare enables a launching systems, respectively. The boosted version has measured response to potentially hostile actions, which a 50% greater average speed than the unboosted round is both consistent with the rules of engagement and which and provides increased effectiveness against highly ma­ does not further escalate hostilities. Decoys can be neuvering targets. The Phase II Evolved Seasparrow launched, for example, in response to emissions from a missile will be incorporated in the SSDS Mk III. targeting radar that may be intended to provoke hostile action while awaiting the actual threat missile launch to INTEGRATED ELECTRONIC WARFARE execute the essentially irrevocable action of hardkill The integration of hardkill weapons (e. g., missiles and weapon engagement. guns) and electronic warfare is key to achieving robust Effective employment of the combat system requires ship self-defense against the anticipated raid densities, the integration of hardkill and softkill weapons, not only particularly in ship classes not confIgured with the ad­ to prevent interference, but to enhance the effectiveness vanced Horizon Search/Weapon Support multifunction of each. This integration includes the use of radar-gen­ radar and Evolved Seasparrow missile. In those ship erated tracks to initiate decoy launch rather than relying classes, an upgraded electronic warfare suite provides a exclusively on electronic support measures detections. It cost-effective enhancement capable of defeating the less also includes selectively scheduling targets for electronic stressing threats. Performance against the supersonic, warfare engagements that would otherwise go unengaged sea-skimming, multimode-guidance threat is stressed with hardkill weapons because of resource limitations because of the inherent dependence of softkill effective- and employing hardkill and softkill weapons in parallel

138 f ohns Hopkins APL Technical Digest. Volume 14. Number 2 (1993) Ship Self-Defense Against Air Threats

Wing Rocket control motor Guidance

Existing RIM-7P/R

Clipped Folding fins wings

Thrust New inertial International Tail New rocket Quad­ Quick vector measurement baseline control motor packable start control unit

Near-term Evolved Seasparrow missile \ International Mk 41 Midcourse Pulsed options Quad-pack uplink (X) continuous-wave illumination

U.S. unique options

Figure 15. The near-term Evolved Seas parrow missile is being developed by an international consortium including Australia, Belgium, Canada, Germany, the Netherlands, Norway, Portugal, Spain, and the United States. International and U.S. unique options are identified; these options are influenced primarily by combat system integration requirements.

when softkill weapons alter the threat characteristics and SUMMARY: AN ENHANCED DEFENSE FOR increase the vulnerability to hardkill weapons. THE LITTORAL ENVIRONMENT Upgrades of existing electronic warfare elements (Fig. 16) are also needed to achieve the desired level of combat Although the recent dramatic geopolitical changes system performance. These upgrades include advanced have all but eliminated the possibility of global war, they digital signal processing for signal discrimination and have introduced new instabilities and accelerated the integration, an adjunct high-sensitivity horizon electronic proliferation of advanced-technology weapons. Motivat­ support measures sensor for sea-skimmer detection, and ed by geopolitical, ethnic, or religious instabilities, lim­ an oftboard active electronic decoy matched to the re­ ited and regional conflicts in littoral environments are duced cross section of the ship. These upgrades will be more likely than they have been in the past. In response integrated into the SSDS Mk IT. The Mk ill concept in­ to this changing threat, the Navy has focused on enhanc­ cludes several additional new technology elements that ing ship self-defense, and the Program Executive Office are fully integrated in the Advanced Integrated Electronic for Ship Defense has endorsed the overall roadmap de­ Warfare System, including enhanced signal processing scribed in this article for upgrading existing weapon for threat identification, active IR countermeasures, and system elements and integrating critical new technolo­ advanced active oftboard decoys. This level of integration gies into the combat system. also requires electronic support measures data of millira­ The enhancements required are primarily driven by the dian accuracy as provided by the precision electronic advanced supersonic, maneuvering, sea-skimming threat support measures sensor described earlier. The SSDS Mk in the cluttered littoral environment. Upgrades dependent ITI integrated electronic warfare suite will provide in­ on each ship class, including sensors, weapons, and their creased effectiveness against the threat, particularly in integration, will be required for effective defense. The those ship classes that do not receive the advanced hard­ necessary sensor improvements include upgrades to the kill weapon systems. existing Mk 23 Target Acquisition System and AN/SPQ-9

Johns Hopkins APL Technical Digest, Volume 14, Number 2 (1993) 139 D. R. Ousborne

With these upgrades, the application of new technol­ ogy, and increased system integration, the surface Navy AN/SLO-32 will be able to defend effectively against the air threat it Today Offboard decoys Active ECM may be forced to encounter in Third World regionaV SOO-82 mute limited conflicts in the littoral environment well into the next century. Naval expeditionary forces will then be able to sustain littoral warfare operations while accomplishing their mission. AN/SLO-32 advanced capability Deceptive ECM and decoy integration Immediate Ship signature reduction capability Hardkili/softkill doctrine ACKNOWLEDGME T: The author thanks Bernard M. Kraus, William T. IR decoy improvements Mason Ill, Sondra H. Ailinger, Bruce A. Bredland, David I. Furst, Benjamin F. Active ECM (FFG 7) Poinsett, Richard J. Prengaman, and John E. Schmiedeskamp for their contributions to the development of this ship self-defense roadmap.

Horizon ESM sensor Advanced processing REFERENCES Softkill effectiveness detection ECM improvements I "First Showing for Anti-Ship Mi iles," lane's Defense Weekly 8(8), 7 Near-term SLO-32 upgrade (Phase E) (1992). capability Advanced active electronic decoy 2Shifrin, C. A, "Russians Forge ew Links at Famborough Air Show," Aviat. Organic/nonorganic data fusion Week Space Technol. 137(12), 29 (1992). Trainable decoy launcher 3Bering-Jensen, H. , "Wrestling with the Arms of Russia," Insight 9(19), 14-16, Cooperative counter-arm techniques 30 (1993). 4Pohling-Brown, P. , "Sales Boom Expected but Careful Marketing Required," Int. Defense Rev. 26, 141-146 (1993). 5 Beal, C. , "Anti-Ship Mi ile Technology: Leaving Well Enough Alone?" Int. Advanced Integrated EW System Def ense Rev. 25, 957-964 (1 992). Precision ESM 6Zhukovsky Flight Re earch Institute, Ru ssia, "Large Anti hip Missile Pow­ Far-term Advanced ECM ered by RocketlRamjet Has 155-Mile Range," Aviat. Week Space Technol. capability Integrated hardkili/softkill 137(8), 64 (1992). Enhanced target identification 7 Gagner, W. P. , "Electronic Combat Access Poses U.S. Weapons Threat," Advanced decoys and launcher Signal 45(4), 70-74 (1990). Active IR countermeasures 8 ANS Mach 2+, The Supersonic Anti-Ship Missile, Euromis ile Brochure, Millimeter-wave ESM/ECM Toulouse, France (1992). 9 Exocel MM 40 Block 2 Anti-Ship Weapon System, Aerospatiale Division, Figure 16. The required electronic warfare enhancements in­ Engins Tactiques Brochure, Chatillon, France (1992). clude sensor, deceptive electronic countermeasures, and offboard IOThe Truly Autonomous Antiship Missile Family, SAAB RBS 15, Combitech decoy upgrades, as well as softkill and hardkill weapon coordina­ Group, Saab Missiles Brochure, Linkoping, Sweden (1992). tion. The upgraded electronic warfare suite provides a cost­ II Jane' s Information Group, lane's Fighting Ships 1993-94, Vol. 96 (1993). effective contribution to air defense, particularly on those ship 12 Whitfield, G. R. , "Optimisation of a Surveillance Radar," in Proc. Insl. Electr. Eng. 113(8), 1277- 1280 (1 966). classes that do not receive the advanced hardkill weapon system 13 Miller, J. T. , Prototype Precision Passive Detection and Tracking (PPD&T) (Ship Self-Defense System Mk III). ECM = electronic countermea­ System Functional Description, JHU/APL FS-92-065 (Oct 1992). sures, ESM = electronic support measures, EW = electronic 14Foxwell, D. , and Hewish M. " ew aval Radars, Active Arrays on the warfare. Horizon," Int. Defense Rev. 25, 945-954 (1992).

THE AUTHOR radars, in addition to the introduction of a horizon IR DOUGLAS R. OUSBORNE is an sensor, a precision electronic support measures sensor, assistant supervisor of APL' S Anti­ and a multifunction radar based on active-element Air Warfare Systems Engineering phased-array technology for horizon search and weapon Group in the Fleet Systems De­ partment. He received a B.S.E.E. support. Weapon improvements include the introduction degree from The University of of the Rolling Airframe missile to provide an immediate Maryland and M.S. degrees in capability in selected amphibious ships, the evolution of electrical engineering and techni­ the Seasparrow missile to address the advanced threat, a cal management from The Johns Hopkins University in 1974, modest upgrade of the Phalanx Close-In Weapon System 1978, and 1985, respectively. Mr. to the Block I Baseline 3 configuration, and electronic Ousbome joined APL in 1974 and warfare enhancements. The integration of these sensors has contributed to the analysis, and weapons is essential to maximizing their effective­ design, development, and evalua­ ness and includes multispectral sensor data fusion, pre­ tion of several long-range and short-range naval air defense sys­ cision cueing, weapon-level data integration, and hard­ tems. He has been a member of kilVsoftkill weapon coordination. the Principal Professional Staff since 1986.

140 lohns Hopkins APL Technical Digest, Volume 14, Number 2 (1993)